#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
	int n;
	cin >> n;
	double sum = 0;
	for (int i = 0;i < n;i++)
	{
		double x;
		cin >> x;
		sum += x;
	}
	cout << fixed << setprecision(4) << sum / n;
	return 0;
}